Syncope
| }} Fainting or syncope (IPA: or ) is a sudden (and generally momentary) loss of consciousness, or blacking out due to the Central Ischaemic Response, because of a lack of sufficient blood and oxygen reaching the brain. The first symptoms a person feels before fainting are dizziness, a dimming of vision, or brownout, tinnitus, and feeling hot. Moments later, the person's vision turns black and he or she drops to the floor (or slumps if seated in a chair). If the person is unable to slump from the position to a near horizontal position they risk dying due to the Suspension Trauma effect. Factors that influence fainting are taking in too little food and fluids, low blood pressure, hypoglycemia, growth spurts, physical exercise in excess of the energy reserve of the body, and lack of sleep. Even standing up too quickly or being in too hot a room can cause fainting. Recommended treatment is to allow the person to lie on the ground with his or her legs a little elevated. As the dizziness and the momentary blindness passes, the person may experience visual disturbances in the form of small bright dots (phosphene). These will also pass within a few minutes. If fainting happens frequently, or if there is no obvious explanation, it is important to see a doctor about it. More serious causes of fainting include cardiac (heart-related) causes such as an abnormal heart rhythm (an arrhythmia), where the heart beats too slowly, too rapidly or too irregularly to pump enough blood to the brain. Some arrhythmias can be life-threatening. Other important cardio-vascular conditions that can be manifested by syncope include subclavian steal syndrome and aortic stenosis. Types It is convenient to think of three types of fainting, or syncope. The usual type is benign and is vaso-vagal. Less common is a pure cardiac syncope. Finally there is syncope from vertebro-basilar arterial disease. Epilepsy appearing as syncope is not considered. Vasovagal syncope The vasovagal type can be considered in two forms: *Isolated episodes of loss of consciousness, unheralded by any warning symptoms for more than a few moments. These tend to occur in the adolescent age group, and may be associated with fasting, exercise, abdominal straining or circumstances promoting vaso-dilatation (eg heat, alcohol). The subject is invariably upright. The tilt-table test, if performed, is generally negative. *Recurrent syncope with complex associated symptoms. This is so-called Neurally Mediated Syncope (NMS). It is associated with any of the following: preceding or succeeding sleepiness, preceding visual disturbance ("spots before the eyes), sweating, light-headedness. The subject is usually but not always upright. A pattern of background factors contributes to the attacks. There is typically an unsuspected relatively low blood volume, for instance, from taking a low salt diet in the absence of any salt-retaining tendency. Heat causes vaso-dilatation and worsens the effect of the relatively insufficient blood volume. That sets the scene, but the next stage is the adrenergic response. If there is underlying fear or anxiety (e.g. social circumstances), or acute fear (e.g. acute threat, needle phobia), the vaso-motor Centre demands an increased pumping action by the heart (flight or fight response). This is set in motion via the adrenergic (sympathetic) outflow from the brain but the heart is unable to meet requirement because of the low blood volume, or decreased return of blood to the heart (abdominal straining). However, the heart's increased left ventricular muscle activity is recognised by the Vaso-Motor Centre via activity in Vagal nerve fibres traveling from the heart to the brain. Normally, the Vagal response would modulate this activity. However, in NMS, the abnormal response that follows is in the exaggerated strength of the return vagal flow, actually causing minor further peripheral vaso-dilatation and slowing the heart decisively - to a point where fainting occurs. In other words, an adrenalin effect causes an over-compensation by the Vagus. Interestingly, some people faint lying in a dentist's chair after receiving adrenalin in a local anaesthetic, endorsing the explanation. The tilt-table test typically evokes the attack. Much of this pathway was discovered in animal experiments by Bezold (Vienna) in the 1860s. In animals, it may represent a defense mechanism when confronted by danger ("playing possum"). This reflex only occurs in some people and may be similar to the animal's reflex. The mechanism described here suggests that a practical way to prevent attacks would be, counter-intuitively, to block the adrenergic signal with a Beta Blocker. But simpler plan is to explain the mechanism, discuss causes of fear, and optimise salt as well as water intake. Pure cardiac syncope Fainting can also occur if pressure on the carotid artery in the neck triggers a vagal signal to the Vaso-Motor Centre, reflexly causing a vagal response to slow the heart. A pure cardiac arrhythmia is a serious matter that can appear as syncope but this is unusual. Severe narrowing of the Aortic Valve leading to syncope is included for completeness. Syncope from vertebro-basilar arterial disease Arterial disease in the upper spinal cord, or lower brain, causes syncope if there is a reduction in blood supply, which may occur with extending the neck or after drugs to lower blood pressure. Particular causes *Carotid sinus syncope *Hair-grooming syncope *Heat syncope *Laughter-induced syncope *Micturition syncope *Stretch syncope Clinical symptoms If the patient states, "I felt dizzy with blurry vision, muscle weakness, during the fall I bumped my knee, hit my head and passed out," then it is not syncope, it is termed pre or near-syncope. If the patient states, "I felt dizzy, shadows came over my eyes, and when I woke up I was lying on the floor," then it is diagnosed as syncope. Patients who experience a syncoptic episode do not remember falling. Syncope in children Syncope in older adults Syncope in mental health settings Syncope in occupational settings See also *Dizziness *Neurocardiogenic syncope *Orthostatic hypotension (blackout after rising) *Postural orthostatic tachycardia syndrome *Presyncope *Shock *Syncope (phonetics), the loss of one or more sounds from the interior of a word, especially the loss of an unstressed vowel *Vertigo References Books *Bruni, J. (1991). Episodic impairment of consciousness. Boston, MA, England: Butterworth Heinemann Publishers. Papers *Abubakr, A., & Wambacq, I. (2005). The diagnostic value of EEGs in patients with syncope: Epilepsy & Behavior Vol 6(3) May 2005, 433-434. *Adler, P. S., France, C., & Ditto, B. (1991). Baroreflex sensitivity at rest and during stress in individuals with a history of vasovagal syncope: Journal of Psychosomatic Research Vol 35(4-5) 1991, 591-597. *Aicardi, J., Gastaut, H., & Mises, J. (1988). Syncopal attacks compulsively self-induced by Valsalva's maneuver associated with typical absence seizures: A case report: Archives of Neurology Vol 45(8) Aug 1988, 923-925. Australian and New Zealand Journal of Family Therapy Vol 6(3) Sep 1985, 145-150. *Anderson, K. W., Taylor, S., & McLean, P. D. (1996). Panic disorder associated with blood-injury reactivity: The necessity of establishing functional relationships among maladaptive behaviors: Behavior Therapy Vol 27(3) Sum 1996, 463-472. *Balbela, G. V., Achigar, G. L., Pintos, A., de Leon, A. V., Amaral, L. V., & Banizi, P. F. (2007). Syncope, presyncope and dizziness in the elderly: Usefulness of the head-up tilt test in the diagnostic process: Revista Espanola de Geriatria y Gerontologia Vol 42(1) Jan-Feb 2007, 11-19. *Berrut, G., Hommet, C., & Beauchet, O. (2007). Loss of consciousness in the elderly: Psychologie & NeuroPsychiatrie Du Vieillissement Vol 5(2) Jun 2007, 101-120. *Blount, R. L., Morris, J. A. B., Cheng, P. S., Campbell, R. M., & Brown, R. T. (2004). Parent and Child Psychological Factors in Pediatric Syncope and Other Somatic Symptoms: Journal of Consulting and Clinical Psychology Vol 72(4) Aug 2004, 597-604. *Bonekat, H. W., Miles, R. M., & Staats, B. A. (1987). Smoking and cough syncope: Follow-up in 45 cases: International Journal of the Addictions Vol 22(5) May 1987, 413-419. *Bonk, V. A. (2000). Interventions to reduce syncopal reactions in first-time blood donors. Dissertation Abstracts International: Section B: The Sciences and Engineering. *Bordier, P., Garrigue, S., Lanusse, S., Margaine, J., Robert, F., Gencel, L., et al. (2006). Cardiovascular Effects and Risk of Syncope Related to Donepezil in Patients with Alzheimer's Disease: CNS Drugs Vol 20(5) 2006, 411-417. *Bordier, P., Lanusse, S., Garrigue, S., Reynard, C., Robert, F., Gencel, L., et al. (2005). Causes of Syncope in Patients with Alzheimer's Disease Treated with Donepezil: Drugs and Aging Vol 22(8) 2005, 687-694. *Brockington, I. (2006). Early postpartum syncope, delirium and stupor: Archives of Women's Mental Health Vol 9(6) Nov 2006, 347-348. *Byars, K. C., Brown, R. T., Campbell, R. M., & Hobbs, S. A. (2000). Psychological adjustment and coping in a population of children with recurrent syncope: Journal of Developmental & Behavioral Pediatrics Vol 21(3) Jun 2000, 189-197. *Chuang, Y.-M., Hu, H.-H., & Pan, P.-J. (2005). Cerebral Syncope: Insights from Valsalva Maneuver: European Neurology Vol 54(2) Oct 2005, 98-102. *Dijk, N. V., Colman, N., Dambrink, J. H. A., & Wieling, W. (2003). Pilots with vasovagal syncope: Fit to fly? : Aviation, Space, and Environmental Medicine Vol 74(5,Sect1) May 2003, 571-574. *Donker, D. N., Robles de Medina, E. O., & Kieft, J. (1972). Micturition syncope: Electroencephalography & Clinical Neurophysiology Vol 33(3) Sep 1972, 328-331. *Freeman, R. (2008). A treatment for neurally mediated syncope? (Don't) hold your breath: Annals of Neurology Vol 63(3) Mar 2008, 265-267. *Gastaut, H., Zifkin, B., & Rufo, M. (1987). Compulsive respiratory stereotypies in children with autistic features: Polygraphic recording and treatment with fenfluramine: Journal of Autism and Developmental Disorders Vol 17(3) Sep 1987, 391-406. *Giza, E., Kyriakou, P., Liasides, C., & Dimakopoulou, A. (2008). Glossopharyngeal neuralgia with cardiac syncope: An idiopathic case treated with carbamazepine and duloxetine: European Journal of Neurology Vol 15(5) May 2008, e38-e39. *Gordon, N. (2008). Neurally mediated syncope: Journal of Pediatric Neurology Vol 6(1) 2008, 1-4. *Kenny, R. A., Shaw, F. E., O'Brien, J. T., Scheltens, P. H., Kalaria, R., & Ballard, C. (2004). Carotid sinus syndrome is common in dementia with Lewy bodies and correlates with deep white matter lesions: Journal of Neurology, Neurosurgery & Psychiatry Vol 75(7) Jul 2004, 966-971. *Khurana, D., Valencia, I., Kruthiventi, S., Gracely, E., Melvin, J., Legido, A., et al. (2008). Correspondence on "Electroencephalography (EEG) with ocular compression in the diagnosis of breath-holding spells or syncope." Journal of Child Neurology Vol 23(6) Jun 2008, 716-717. *Kowacs, P. A., da Silva Junior, E. B., dos Santos, H. L., da Rocha, S. B., Simao, C., de Meneses, M. S., et al. (2005). Syncope or epileptic fits? Some examples of diagnostic confounding factors: Arquivos de Neuro-Psiquiatria Vol 63(3-A) Sep 2005, 597-600. *Kravtsov, Y. I., & Seliverstova, G. A. (1989). Mechanisms of the formation of vegetative dysregulation during neurogenous syncopes in childhood: Zhurnal Nevropatologii i Psikhiatrii imeni S S Korsakova Vol 89(11) 1989, 37-43. *Kravtsov, Y. I., & Seliverstova, G. A. (1991). Mechanisms of the development of autonomic disregulation in neurogenic syncopes in childhood: Soviet Neurology & Psychiatry Vol 24(1) Spr 1991, 26-36. *Lee, P. W. H., Leung, P. W. L., Fung, A. S. M., & Low, L. C. K. (1996). An episode of syncope attacks in adolescent schoolgirls: Investigations, intervention and outcome: British Journal of Medical Psychology Vol 69(3) Sep 1996, 247-257. *Leitch, A., McGinness, P., & Wallbridge, D. (2007). Calculate the QT interval in patients taking drugs for dementia: BMJ: British Medical Journal Vol 335(7619) Sep 2007, 557. *Lively, M. W. (2001). Syncope and neurologic deficits in a track athlete: A case report: Medicine & Science in Sports & Exercise Vol 33(3) Mar 2001, 345-347. *Lopez, M. R., Freeman, R., & Schomer, D. (2002). Spindle coma secondary to vasovagal syncope: Epilepsy & Behavior Vol 3(3,Pt1) Jun 2002, 289-291. *Maas, R., Ventura, R., Kretzschmar, C., Aydin, A., & Schuchert, A. (2003). Syncope, driving recommendations, and clinical reality: Survey of patients: BMJ: British Medical Journal Vol 326(7379) Jan 2003, 21. *Mathew, R. J., Wilson, W. H., & Davis, R. (2003). Postural syncope after marijuana: A transcranial Doppler study of the hemodynamics: Pharmacology, Biochemistry and Behavior Vol 75(2) May 2003, 309-318. *Matsui, H., Nishinaka, K., Oda, M., Komatsu, K., Kubori, T., & Udaka, F. (2006). Does cardiac metaiodobenzylguanidine (MIBG) uptake in Parkinson's disease correlate with major autonomic symptoms? : Parkinsonism & Related Disorders Vol 12(5) Jun 2006, 284-288. *Mazzuca, M., & Thomas, P. (2007). Self-induced stretch syncope of adolescence: A video-EEG documentation: Epileptic Disorders Vol 9(4) Dec 2007, 413-417. *Mohanty, A. K., Flannery, M. T., Johnson, B. L., & Brady, P. G. (2006). A Sharp Right Turn: New England Journal of Medicine Vol 355(5) Aug 2006, 500-505. *Morris, J. A.-B. (1998). Family environment and parents' psychological and somatic symptoms as predictors of affective and physical symptom behaviors in unexplained pediatric syncope. Dissertation Abstracts International: Section B: The Sciences and Engineering. *Morris, J. A. B., Blount, R. L., Brown, R. T., & Campbell, R. M. (2001). Association of parental psychological and behavioral factors and children's syncope: Journal of Consulting and Clinical Psychology Vol 69(5) Oct 2001, 851-857. *Nambudiri, D. E., Mirchandani, I. C., & Young, R. C. (1989). Two more cases of trazodone-related syncope in the elderly: Journal of Geriatric Psychiatry and Neurology Vol 2(4) Oct-Dec 1989, 225. *Nath, S., & Kenny, R. A. (2005). Syncope in the older person: A review: Reviews in Clinical Gerontology Vol 15(3-4) 2005, 219-235. *Norcliffe-Kaufmann, L. J., Kaufmann, H., & Hainsworth, R. (2008). Enhance vascular responses to hypocapnia in neurally mediated syncope: Annals of Neurology Vol 63(3) Mar 2008, 288-294. *Perrig, S., & Jallon, P. (2008). Is the first seizure truly epileptic? : Epilepsia Vol 49(Suppl 1) Jan 2008, 2-7. *Piovesan, E. J., Sobreira, C. F., Scola, R. H., Lorenzoni, P. J., Lange, M. C., Werneck, L. C., et al. (2008). Episodic migraine associated with postural orthostatic tachycardia syndrome and vasovagal syncope: Migraine triggers neuromediated syncope: Arquivos de Neuro-Psiquiatria Vol 66(1) Mar 2008, 77-79. *Poulsen, N. B. (1982). Anni: An average client? : Udkast Vol 10(3-4) 1982, 348-413. *Riviello, J. J., & Rioux, S. D. (1993). Hair-braiding and combing-induced syncope: A paroxysmal nonepileptic event: Journal of Epilepsy Vol 6(2) 1993, 115-117. *Roden, S. K. (2001). Blood-injection-injury phobia in a commercial aviator: A case report: Aviation, Space, and Environmental Medicine Vol 72(12) Dec 2001, 1138-1140. *Rollinson, N. L. (2005). Understanding and Managing Neurally Mediated Syncope in the Adolescent: The Journal of School Nursing Vol 21(4) Aug 2005, 200-207. *Santhouse, J., Carrier, C., Arya, S., Fowler, H., & Duncan, S. (2007). Comparison of self-reported quality of life between patients with epilepsy and neurocardiogenic syncope: Epilepsia Vol 48(5) May 2007, 1019-1022. *Schmidt, R. T. (1975). Personality and fainting: Journal of Psychosomatic Research Vol 19(1) 1975, 21-25. *Schneck, J. M. (1984). Syncope after ingestion of one tablet of perphenazine 2 mg amitriptyline HCl 25 mg during psychotherapy: Journal of Integrative & Eclectic Psychotherapy Vol 3(1) Sep 1984, 7-9. *Schondorf, R., & Shen, W.-K. (2006). Syncope: Case Studies: Neurologic Clinics Vol 24(2) May 2006, 215-231. *Seim, R. W., Willerick, M. S., Gaynor, S. T., & Spates, C. R. (2008). Circumventing the vasovagal fainting response: A novel method of in vivo exposure for injection phobia: Clinical Case Studies Vol 7(5) Oct 2008, 409-422. *Seri, S., Cerquiglini, A., & Harding, G. F. A. (2006). Visually induced syncope: A nonepileptic manifestation of visual sensitivity? : Neurology Vol 67(2) Jul 2006, 359-360. *Sim, V., Pascual, J., & Woo, J. (2002). Evaluating elderly patients with syncope: Archives of Gerontology and Geriatrics Vol 35(2) Sep-Oct 2002, 121-135. *Sledge, W. H., & Boydstun, J. A. (1979). Vasovagal syncope in aircrew: Psychosocial aspects: Journal of Nervous and Mental Disease Vol 167(2) Feb 1979, 114-124. *Sledge, W. H., & Boydstun, J. A. (1980). The psychiatrist's role in aerospace operations: American Journal of Psychiatry Vol 137(8) Aug 1980, 956-959. *Sledge, W. H., & Boydstun, J. A. (1982). Syncope in aircrew: Aviation, Space, and Environmental Medicine Vol 53(3) Mar 1982, 258-265. *Smith, M. S., & Glass, S. T. (1989). An adolescent girl with headache and syncope: Journal of Adolescent Health Care Vol 10(1) Jan 1989, 54-56. *Smith, P. M. (2004). Giving oneself to writing: Syncopations in the life of a woman religious: International Journal of Qualitative Studies in Education Vol 17(1) Jan-Feb 2004, 29-46. *Spallone, G. (1980). A microsocial analysis according to systems theory: The hospital, the admission, the symptom: Bollettino di Psicologia Applicata No 155-156 Jul-Dec 1980, 141-150. *Spudis, E. V., Penry, J. K., & Gibson, P. (1986). Driving impairment caused by episodic brain dysfunction: Restrictions for epilepsy and syncope: Archives of Neurology Vol 43(6) Jun 1986, 558-564. *Stephenson, J., Breningstall, G., Steer, C., Kirkpatrick, M., Horrocks, l., Nechay, A., et al. (2004). Anoxic-epileptic seizures: Home video recordings of epileptic seizures induced by syncopes: Epileptic Disorders Vol 6(1) Mar 2004, 15-19. *Stephenson, J. B. P. (2006). Visually induced syncope: A nonepileptic manifestation of visual sensitivity? : Neurology Vol 67(2) Jul 2006, 193. *Stevens, H. (1987). Syncope, seizures and stress: Stress Medicine Vol 3(1) Jan-Mar 1987, 41-49. *Styczynski, G., Dobosiewicz, A., Abramczyk, P., & Styczynska, M. (2008). Internal jugular vein valve insufficiency in cough syncope: Neurology Vol 70(10) Mar 2008, 812-813. *Szigetvari, P. (2007). Branching onsets and syncope in English: Language Sciences Vol 29(2-3) May 2007, 408-425. *Theorell, T., Liljeholm-Johansson, Y., Bjork, H., & Ericson, M. (2007). Saliva testosterone and heart rate variability in the professional symphony orchestra after "public faintings" of an orchestra member: Psychoneuroendocrinology Vol 32(6) Jul 2007, 660-668. *Thijs, R. D., & van Dijk, J. G. (2008). How do feelings cause faints? : Clinical Neurophysiology Vol 119(9) Sep 2008, 1945-1946. *Thijs, R. D., van Dijk, J. G., Stephenson, J. B. P., & Wieling, W. (2007). Mind-stretching faints: Epileptic Disorders Vol 9(4) Dec 2007, 418-423. *Torgovnick, J., Sethi, N. K., & Arsura, E. (2008). Aripiprazole-induced orthostatic hypotension and cardiac arrhythmia: Psychiatry and Clinical Neurosciences Vol 62(4) Aug 2008, 485. *Tupala, E., Niskanen, L., & Tiihonen, J. (1999). Transient syncope and ECG changes associated with the concurrent administration of clozapine and diazepam: Journal of Clinical Psychiatry Vol 60(9) Sep 1999, 619-620. *Ungar, A., Mussi, C., Del Rosso, A., Noro, G., Abete, P., Ghirelli, L., et al. (2006). Diagnosis and Characteristics of Syncope in Older Patients Referred to Geriatric Departments: Journal of the American Geriatrics Society Vol 54(10) Oct 2006, 1531-1536. *Vein, A. M., Biniaurishvili, R. G., Eligulashvili, T. S., & Kuz'mina, Z. I. (1986). Changes in paroxysmal activity, the spectral characteristics of the EEG, and visual evoked potentials following sleep deprivation in patients with epilepsy or syncope: Soviet Neurology & Psychiatry Vol 19(4) Win 1986-1987, 28-39. *Vingerhoets, A. J. (1984). Biochemical changes in two subjects succumbing to syncope: Psychosomatic Medicine Vol 46(2) Mar-Apr 1984, 95-103. *Vingerhoets, A. J., & Schomaker, L. R. (1984). Fainting as a stress response: Psychological and physiological aspects: Gedrag: Tijdschrift voor Psychologie Vol 12(1-2) 1984, 46-59. *Voge, V. M., Hastings, J. D., & Drew, W. E. (1995). Convulsive syncope in the aviation environment: Aviation, Space, and Environmental Medicine Vol 66(12) Dec 1995, 1198-1204. *Wilting, I., Smals, O. M., Holwerda, N. J., Meyboom, R. H., De Bruin, M. L., & Egberts, T. C. G. (2006). QTc Prolongation and Torsades de Pointes in an Elderly Woman Taking Fluoxetine: American Journal of Psychiatry Vol 163(2) Feb 2006, 325. *You, C.-F., Chong, C.-F., Wang, T.-L., Hung, T.-Y., & Chen, C.-C. (2007). Unrecognized paroxysmal ventricular standstill masquerading as epilepsy: A Stokes-Adams attack: Epileptic Disorders Vol 9(2) Jun 2007, 179-181. External links *2004 European Society of Cardiology Guidelines on Management (Diagnosis and Treatment) of Syncope. *Dysautonomia Information Network *Dysautonomia Youth Network of America, Inc. *Dysautonomia Support Network Corp. *Tilt table test *http://www.youtube.com/watch?v=uEE49bgEEDc&NR Category:Blood presssure disorders Category:Consciousness Category:Symptoms